FIG 6 .

Exogenous menaquinone rescues the growth and pilus assembly defects of the ΔubiE mutant. (A) Growth of the wild-type (WT) strain (solid circles), ΔubiE (gray squares), ΔubiE/pUbiE (gray inverted triangles), and ΔubiE strains in the presence of 0.1 mM menaquinone-4 (MK-4 [triangles]) was measured by optical density (OD₆₀₀). The results are representative of three independent experiments performed in duplicate. ***, P ≤ 0.0001, as determined by paired two-tailed t test with GraphPad Prism. (B) A. oris strains were streaked as a broad band on HIA plates. A 3-μl drop of 50 mM MK-4 was placed on the border of the streaks, and the growth of the strains at 37°C was recorded after 48 h. Areas of MK-4 diffusion are marked with dashed lines. (C to F) A. oris cells of the WT and ΔubiE, ΔubiE/pUbiE, and ΔubiE mutants grown in the presence of 0.1 mM MK-4 were subjected to immunogold labeling with anti-CafA as described in the legend to Fig. 4. Scale bars indicate 0.5 µm.